insincere

Not sincere; not genuine.

Habitually phony or dishonest.

Not genuine; unsound; imperfect.

Not sincere in character; making a false or hypocritical show of opinions or feelings.

Not sincere in quality; simulated; deceptive; false.

Synonyms Disingenuous, uncandid, double-faced, hollow.

Not being in truth what one appears to be; not sincere; dissembling; hypocritical; disingenuous; deceitful; false; — said of persons; also of speech, thought; etc..

Disappointing; imperfect; unsound.

not sincere

not serious